N-Methyl-D-aspartate receptors as novel M1 macrophage-specific biomedical imaging nanoplatform agents: feasibility of targeted imaging in an inflammatory mice model.

N-Methyl-D-aspartate receptor (NMDAR)-antibody-labeled mesoporous silica nanoparticles (NMDAR-PEG-DID@MSNs) were developed as a fluorescence imaging tool for M1 macrophage-associated inflammatory diseases. The nanoparticles were synthesized by conjugating NMDAR antibodies, polyethylene glycol (PEG), and the fluorescent dye DID onto mesoporous silica nanoparticles. Their imaging capability was evaluated in chronic (turpentine induced) and acute (lipopolysaccharide and carrageenan-induced) inflammation models, as well as for monitoring the anti-inflammatory effects of dexamethasone. NMDAR-PEG-DID@MSNs enabled the early detection of inflamed lesions, with fluorescence signals persisting for up to 24 hours, and successfully demonstrated the therapeutic efficacy of dexamethasone. These results highlight the potential of this nanoplatform for inflammation diagnosis and therapeutic monitoring.